The overall goal of the Neuropathology Core (Core D) is to collect, characterize, store, and distribute well-characterized brains from autopsy participants from the Clinical Core, consisting of a group of well-documented individuals with Alzheimer disease (AD) and from normal control individuals without neurological disease. Specific Core D aims are: 1) diagnostic neuropathological evaluation of each brain, using a meticulous diagnostic approach, essential to all studies related to and stemming from these subjects. A standardardized approach for neuropathologic assessment is performed using published diagnostic criteria for those brains with recognizable neurodegenerative diseases. Neuropathological diagnosis of Alzheimer disease is based on NIA-Reagan Institute criteria. Other neurodegenerative diseases, coexistent with or instead of AD, will be evaluated by currently available published criteria. 2) Tissue preparation for research, collaboration. Processing and storing tissue from each brain and skeletal muscle sample collected will be performed for subsequent distribution to KU ADCC and other approved investigators to support AD-related research. Core D will contribute neuropathology case information to the NACC database. In order to assist investigators studying animal models of AD and related disorders, neuropathology services provided for study of human tissues will also be made available for animal-based researchers. Core D will also investigate new techniques and products for enhancing tissue preservation related to the proposed studies emphasized by this ADC. There is excellent integration with the other Cores, ranging from provision of tissue for genetic, metabolic studies (MGM Core), clinicopathological correlations (Clinical, Neuroimaging, Education Cores), centralization of data (Data Management Core), reviewing tissue requests (Administration Core), to community and resident education (Education Core). As new criteria for neuropathological assessments, new methodologies, and feedback from the other cores and the AD-neurodegenerative field occurs. Core D will show adaptability in order to implement change in assessments of the brains.